Merge from 3.2:

- Issue #9651: Fix a crash when ctypes.create_string_buffer(0) was passed to file.write()
- Issue #11241: subclasses of ctypes.Array can now be subclassed.

2 files changed, 56 insertions, 0 deletions

diff --git a/Lib/ctypes/test/test_arrays.py b/Lib/ctypes/test/test_arrays.py
index f2a9f07..cfc219e 100644
--- a/Lib/ctypes/test/test_arrays.py
+++ b/Lib/ctypes/test/test_arrays.py
@@ -127,5 +127,57 @@ class ArrayTestCase(unittest.TestCase):
         t2 = my_int * 1
         self.assertTrue(t1 is t2)
 
+    def test_subclass(self):
+        class T(Array):
+            _type_ = c_int
+            _length_ = 13
+        class U(T):
+            pass
+        class V(U):
+            pass
+        class W(V):
+            pass
+        class X(T):
+            _type_ = c_short
+        class Y(T):
+            _length_ = 187
+
+        for c in [T, U, V, W]:
+            self.assertEqual(c._type_, c_int)
+            self.assertEqual(c._length_, 13)
+            self.assertEqual(c()._type_, c_int)
+            self.assertEqual(c()._length_, 13)
+
+        self.assertEqual(X._type_, c_short)
+        self.assertEqual(X._length_, 13)
+        self.assertEqual(X()._type_, c_short)
+        self.assertEqual(X()._length_, 13)
+
+        self.assertEqual(Y._type_, c_int)
+        self.assertEqual(Y._length_, 187)
+        self.assertEqual(Y()._type_, c_int)
+        self.assertEqual(Y()._length_, 187)
+
+    def test_bad_subclass(self):
+        import sys
+
+        with self.assertRaises(AttributeError):
+            class T(Array):
+                pass
+        with self.assertRaises(AttributeError):
+            class T(Array):
+                _type_ = c_int
+        with self.assertRaises(AttributeError):
+            class T(Array):
+                _length_ = 13
+        with self.assertRaises(OverflowError):
+            class T(Array):
+                _type_ = c_int
+                _length_ = sys.maxsize * 2
+        with self.assertRaises(AttributeError):
+            class T(Array):
+                _type_ = c_int
+                _length_ = 1.87
+
 if __name__ == '__main__':
     unittest.main()
diff --git a/Lib/ctypes/test/test_buffers.py b/Lib/ctypes/test/test_buffers.py
index c19c05a..2dc7484 100644
--- a/Lib/ctypes/test/test_buffers.py
+++ b/Lib/ctypes/test/test_buffers.py
@@ -20,6 +20,10 @@ class StringBufferTestCase(unittest.TestCase):
         self.assertEqual(b[::2], b"ac")
         self.assertEqual(b[::5], b"a")
 
+    def test_buffer_interface(self):
+        self.assertEqual(len(bytearray(create_string_buffer(0))), 0)
+        self.assertEqual(len(bytearray(create_string_buffer(1))), 1)
+
     try:
         c_wchar
     except NameError: